Self-igniting engine



July 30, 1929. B STEARNS 1,722,772

SELF IGNITING, ENGINE Original Filed May 29, 1924 6 Sheets Sheet lINVENTOR ATTORNEYS.

y 1929- F. B. STEARNS SELF IGNITING ENGINE Orginal Filed May 29} 1924 esheets-sheet 2- BY I ATTORNEYS. 2

INVENTOR July 30, 1929. STEARNS 1,722,772

SELF IGNITING ENGINE Original Filed May 29, 1924 6 Sheets-Sheet 5INVENTOR M 13. m

' ATTORNEYS.

6 Sheets-Sheet 4 u u E 5 July 30, 1929.

Original Filed May 29, 1924 INVENTOR 9 10 12, 13. m

BY W WM ATTORNEYS.

y 0, 1929. F. B. STEARNS SELF IGNITING ENGINE 6 Sheets- Sheet 5 OriginalFiled May 29, .1924

INVENTOR Sig-mm BY .QkTZXy M [@5517 A ORNEYJ.

July 30, 1929. F. B. STEARNS SELF IGNITING ENGINE Original Filed May29,- 1924 6 Sheets-Sheet 6 INVENTOR bw/ham ATTORNEYS T ii. ill? 1 FRANKIB. LT

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SmF-IGNITUVG ENGINE.

Application filed may 23, 1924, Serial-No. 716,568. Renewed December 20,1925.

whereby compressed air can be introduced inf to the cylinder in suchvolume and at a speed sufficient to completel displace the exhaust gasesafter each exp osion, and to fill the cylinder with a fresh supply ofcompressed air which is further compressed by the compression stroke ofthe piston to ignite the fuel charge.

Another object of my invention resides in providing mechanism wherebythe time at which fuel is injected into the cylinder can be manuallyregulated.

Another object of my invention is to provide mechanism which can benormally regulated to control the volume of fuel which is injected intothe cylinder during each injectionperiod, such regulation, of thequantity of fuel injected, ranging from full capacity of theinjectionports to as small a quantity as is desired.

These and other objects and the invention itself will be more apparentfrom the following detailed description.

head;

In the accompanying drawings,-

Fig. 1 is a side elevation of an engine embodying my invention;

Fig. 2 is a top plan view of the same, the air compression beingpartially broken away;

Fig. -3 is an elevation of another side of the engine; 3

Fig. 4 is a vertical sectional view of the engine taken on line 4-4 ofFig. 2;

Fig. 5 is a fragmentary elevation of another side of the engine showingthe eccentric shaft and the mechanism operated thereby;

Fig. 6 is a fragmentary section of a portion of the fuel valve operatingmechanism; I

Fig. 7 is an end elevation of the mechanism for adjusting the turning ofthe fuel valve operating mechanism;

Fig. 8 is a top plan view of the cylinder Fig. 9 is a sectional view ofthe same taken on line 9--9 of Fig. 8; r

Fig. 10 is a side elevation of the same;

Fig. 11 is another side elevation of the same;

Fig. 12 is a perspective view of the head shown partially in section;and

Fig. 13 is a fragmentary vertical section of the fuel nozzle with thevalve element seated therein.

Fig. 14 is a longitudinal, medial, sectional view of a form ofcompressor which may be employed co-operatively as apart of themechanism of my invention, the crankshaft illustrated in Fig. 14 beingthe same crankshaft illustrated in Fig. 4 as broken off at the left sideof the drawing, the broken-0E portion in Fi 14 joining with thebroken-0d portion of Fig. 4.

Referring now to the drawings by characters of reference, 15 illustratesa crank case having a crank shaft 16 mounted in bearings therein. Acylinder 17 is secured upon the crank case and is in open communicationwith the interior thereof. A piston 18 is mounted to reciprocate in thecylinder and is provided with a wrist pin 19 to which the piston rod 20is connected, the other end of the rod being connected to the crankshaft. The cylinder is provided with a pair of oppositely disposedexhaust ports 21 arranged so that they are opened by the piston when inits lower position. The parts of the engine, so far described, are aconventional design of the twocycle type, and a further descriptionofthese' parts is therefore not thought to be necessary.

An air compressor 22 is secured upon the crank case and is rovided witha pair of outlet pipes 23 wh1ch are arranged to convey the compressedair to the cylinder head 24, a cam shaft, or eccentric shaft 25 iscarried by bearings 26 secured upon the crank case, and a gear 27 issecured thereto. This gear is driven by the chain 28 which extendsaround the gear 29 secured to the crank shaft. A shaft 30 extendseccentrically from one end of the'cam shaft and a compressor operatingrod 31 is adapted to be reciprocated thereb The compressor illustratedherein is the su j ect matter of my pending application, Serial No.715,538, filed May 24, 1924, to which reference may be had for thedetails and operation of the parts not shown herein.

A compressor cylinder 131 is secured upon the top of the crank case inopen commumcation with the interior thereof and adjacent ports 136 areprovided in the cylinder wall intermediate the inlet ports and the endof the cylinder. The pipes 23 are secured to the compressor cylinderand'provide passages for conducting the compressed air from the outletports to the engine head.

The compressor cylinder is providedwith a closure head 137 which issecured upon the upper end thereof by bolts 138, and an apertured hub139 extends centrally therefrom into the cylinder. The inner end of thehub terminates in an interiorly extending flange 140 formed to provide abearing through which a stem 141 is slidably mounted. A hollow packingnut 142 is threaded into the upper end of the apertured hub portion ofthehead and provides a bearing'for the stem 141 which extendstherethrough. A stationar hollow valve element is mounted within theupper end of the compressor, cylinder and is positioned in opposedrelation to the reciprocating piston 132. The stationary'valve elementconsists of an annular head 143 of smaller diameter diametersubstantiall than the cylinder, having a skirt portion 144 extendingtherefrom terminatin in an outwardly extending flange 145 oi an outsidethat of the bore of the cylinder. The anged portion of theskirt-issecured against the cylinder head by screws 146. The skirt 144of the stationary valve element, including the flanged end, is

1 provided with equally spaced slots 147 which that t ey will extendthrough the slots in the skirt portion of thevalve element and areprovided adjacent their outer ends with bolt holes 153. A slidablecylindrical valve element 154 is positioned within the compressorcylinder, beneath the spider, and is secured against the under side ofthe arms by bolts 155, which project through the holes 153. The

cylindrical movable valve is formed of a diameter to slidably engage theinner wall of the cylinder, and an expanding ring 156 is positloned inan annular recess 157 formed in the outer wall of this valve element.The inner wall of the cylindrical valve element is provided with aplurality of slots 158 which extend lengthwise thereof and terminateadjacent the lower end ofthe skirt.

The valve element 154 which is secured to the arbor is of such thicknessthat it will engage the skirt 144 of the stationary valve element andthe inner wall of the cylinder.

The valve element 154 is vertically reciprocated by the movement of thestem 141 to which the spider is secured. -The arrangement of the movablevalve element is such that it will cover the air inlet ports in thecylinder wall when in its lower position, and when in such position thelower ends of the slots 158 will lie beneath the head of the stationaryvalve element, whereby establishing'communication between thecompression chamber beneath the head of the stationary valve element,and the outlet orts'136. Upward movement of the movab e valve elementfirst covers the slots 158 beneath the skirt of the stationary valveelement and then uncovers the inlet ports 135. The slots 147 throughwhich the spider arms extend, per mit the spider to be reciprocated alimlted distance, thereby reciprocating the movable valve elementbetween the cylinder wall and the skirt beneath the cylinder head. Theexpanding rings 156 and 148 will engage respectively the cylinder walland the inner wall of the movable valve member thereby providing asealing which materially increases the compression of air within thecompressionichamber and prevents leakage from The mechanlsms foroperatin the movable compressor piston and the mova 1e valve element areso arranged, and operated, that as the compressor piston starts down,the inlet ports are uncovered by the movable annular valve element, andthey remain uncovered until the compression piston is at the bottom ofits travel. A fresh supply of air passes into the compression chamberthrough the ports when uncovered. As the compressor piston starts itsupward travel, the inlet ports will be closed by the annular valveelement and, as the annular valve element moves down the slots in theinner wall thereof, will extend below the head of the stationary valveelement,-permitting the compressed air to pass through passages formedby the slots and the skirt of the stationary valve element, into theupper portion of the cylinder and the pipes 121.

It will be observed that the valve elements control both the passages ofair into the cylinder, and the passage of compressed air from thecompression chamber.

The cylinder head 24 is formed with a central aperture 32 which extendsaxially therethrough and receives the fuel feeding device. A pair ofconduits 33 extend through the head and are arranged so that c'ompressedair can be directed thereby downwardly into the cylinder. The conduitsextend inwardly, from opposite sides of the head, in a horizontal planeand are offset with respect to each other so that they extend on sidesthereof. The sides of the head adjacent the conduits are provided withflanges 34 to which the pipes 23 from the compressor are secured bybolts 35, establishing communication between the conduits and thecompressor. It will be observed that the conduits feed the compressedair downwardly into the cylinder, and that they are of large area sothat a large volume of compressed air can pass into the cylinder aftereach explosion therein. The head is provided with peripheral apertures13 through which studs extend to secure the head upon the cylinder.Suitable passages 36 are provided within the head, so that a coolingagent may circulate therethrough in the conventional manner. Guides 37extend axially into the downwardly extending portion of the conduits andremovable guides 38 are inserted therein. Valves 39 are arranged to seatagainst the wall adjacent the outlet ends of the conduits in the head,and stems 40 extend therefrom through the guides 38. Retainers 41 aresecured adjacent the upper end of thev stems. and coil springs 42,encircling the valve stems bear against the retainers at one end andagainst the engine head at their other end. The springs are provided tonormally maintain the valves 39 in position to close the conduits, sothat compressed air will pass into the cylinder only while the valvesare mechanically unseated. M

A cam 44 is secured to the eccentric shaft 25 adjacent one side of thecylinder for actuating the valve operating mechanism. Bearings 45 extendfrom the cylinder and are provided with vertically extending aperturesin alignment with the cam. A rod '46 extends through the bearings 45 andis provided at its lower end with a plate 47 which the cam engages tomove the rod upwardly. A pair of levers 48 are pivotally connected atone end to the upper end of the rod, and are adapted to be actuated bythe movement thereof. Parallel shafts 49 are rotatably mounted inbrackets50 which are secured upon the en-, gine head, and rocker arms 51are secured to one end of these shafts and are adapted to be actuated bythe levers 48, the rocker arms having recesses 52 provided in the undersides thereof within which theends of the levers 48 engage. Rocker arms53 are secured to the shafts 49 and are provided with bifurcated ends54, which carry rollers 55. The rocker arms 53 are arranged so that therollers carried thereby will engage the end of the valve stems 40,moving them downwardly when the shafts 49 are rotated by the camoperated mechanism. It will be seen that the cam can be placed upon theeccentric shaft to move the valve operating mechanism at the timedesired, relative to the other operating parts of the engine, and thecam is designed to retain the mechanism is an upward position suflicientlength of time to maintain the valves in open position long enough sothat enough compressed air passes into the cylinder from the conduits tocompletely scavange the burnt gases while the exhaust ports are open,and

to fillthe cylinder with vcompressed air when w the exhaust ports areagain closed.

A fuel injector head 56 is secured upon the cylinder head and isprovided with a hub porcase, this shaft being parallel with theeccentric shaft and located on the opposite side of the engine cylindertherefrom. A gear 62 is securedto the pump shaft and is driven by achain 63 which extends around a gear 64 secured to the eccentric shaft.A pump rod 65 is secured to the pump shaft and is reciprocated thereby.A pipe 66 leads from a source of fuel supply and is connected with thepump.-

The lower hub portion 67 of the injector head is formed to extendinto-the aperture 32 in the engine head and its lower end is of reduceddiameter and threaded externally. An aperture 58 extends axially throughthe injector head and the hubs which extend 'bein held against the endof the hub by a cap 1 which is screwed upon the threaded end of the hub.The nozzle extends through the opening 32 in the head and projects intothe explosion chamber beneaththe head,

being provided with fuel outlet ports 72 for.

spraying fuel into the cylinder. The aper- I screwed upon the upper endof the hub 76,

and a valve closure element extends through the bearings and theaperture in the hubs. The lower end of the valve is conieally formed sothat it will extend into'the nozzle and seat against the conicalshoulder 120 when in its lower position to close the outlet ports 72,and is of less diameter than theinterior of the nozzle so that fuel canpass through the nozzle while it extends therein. A retainer 79 issecured to the valve element, and a coilspring 80 extends around thevalve element, bearing against the retainer and the underside of thebearing 77. This spring will normally press the valve downwardly so thatit closes the seat in the nozzle, to prevent passage of fuelinto thecylinder. The upper end of the valve element is threaded and nuts 81 arescrewed thereupon. It will be seen that the distance the conical portionof the valve element is moved from the seat 120 will determine thevolume of fuel permitted to be sprayed with the cylinder.

The upper end of the sleeve 75 is provided with an outwardly extendingflange 82 having a bifurcated bracket portion 83 extending upwardlytherefrom. A plurality of studs 84 are screwed into the flange 82 andare ar ranged to provide supporting standards for a support 85. Thestuds are threaded into the support and nuts 86 are provided for thestuds to maintain the support thereon. The

support is provided with a threaded passage which is-in verticalalignment with the valve element, and a threaded rod 87 for regulatingthe distance the valve can be raised, is adapted to be screwed throughthe passage in the support. A handle 14 extends through the outer end ofthe rod 87 so that it can be manually operated to regulate the positionthereof. It will be seen that the regulating element can be screwedtoward the valve so that it will engage the end thereof when the valveis in its lowest position closing the ports in the nozzle, and also thatthe element can be adjusted to permit the valve to be raised from theseat any distance desired between the closed position and the fully openposition. The regulating element can in this manner be adjusted tocontrol opening movement of the valve and the volume of fuel which ispermitted to pass into the cylinder through the nozzle ports will beregulated thereby.

Mechanism is operated by the eccentric shaft for lifting the valve andincludes a rocker arm 90 which is pivoted intermediate its ends andpivotally mounted in the bifurcated portion of the bracket 83. Therocker arm is arranged so that one end 91 thereof, which is bifurcated,will engage one of the. nuts 81 which is screwed upon the valve member.Rocking of this arm will lift the valve from its seat, where itisnorinally retained by the spring 80, a full movement thereof, or thelength of movement permitted by the element 87 if adjusted to limit themovement of the valve. A rod 92 extends through and is slidable in asleeve 93, which extends into an aperture in the end 94 of the rockerarm. The end of the rod is threaded and a retainer 95 is screwedthereon, being secured in desired position by lock nuts 96. A coilspring 97 surrounds the rod, and bears against the upper end of thesleeve 93. The retainer is positioned to create sufficient tension uponthe spring, so that it will operate the rocker arm with the rod. It willbe seen, however. that when the movement of the valve, and the rockerarm is limited, so that they will not move their normal distance. thatthe spring 97 will permit the rod to continue its entire movementwithout affecting the rocker arm.

The lower end of the rod 92 is pivotally connected by a connector to oneend of a link 98 which link is arranged to underlie the eccentric shaft.The other end of this link is pivotally secured within the bifurcatedend of a rocker arm 99 secured to shaft 100 which is rotatably mountedin a pair of brackets 101 secured to the crank case. A handle 102 issecured at one end to the shaft 100 and when moved back and forth willrotate the shaft, thereby changing the normal position of the link 98. Aroller 103 is carried by the link 98 and is adapted to be engaged by acam 104 secured to the eccentric shaft. As this cam rotates it strikesthe roller 'securedto the link, moving'the floating end of the linkdownwardly and thereby moving the rod 92 therewith.

The relation of the link 97 to theoperating cam is regulated by the handlever. so that the time at which the cam strikes the roller can beregulated so that it can be advanced or retarded, thereby actuating thefuel valve correspondingly. j

A curved sector 105 extends from the en gine c linder and bolts 106 aresecured to the hand ever 102, so that the sector will extendtherebetween. A plate 107 extends across the end of the bolts andprovides a support for a stud 108. By screwing the stud so that itengages the sector the lever can be maintained stationary. Thismechanism serves to permit the handle to be adjusted to change theinjection and for controlling the volume of fuel injected when the fuelvalve is Open ated, both of such mechanisms being adjustable while theengine is operating or while it is not in operation. I have alsoprovided an engine in which compressed air 'can be introduced after eachexplosion to completely scavange the cylinder of burnt gases and tocompletely charge the cylinder with a full volume of compressed air atthe beginnin of the compression stroke of the piston. he variousmechanisms are all driven from arr eccentric shaft and can be regulatedto be operated in the succession desired.

Various chan es can be made in the em bodiment descri ed withoutdeparting from the spirit of m invention and the scope of the appended caims.

1. n combination with an engine cylinder of a compressor for supplyingair to the engine cylinder said compressor comprising a cylinder and apiston reciprocable therein, of'a pair of inlet ports in the head of theengine cylinder and a plurality of exhaust ports in a lateral wall ofthe engine cylinder, of a piston disposed within the engine cylinder andreciprocable therein, said piston adapted to uncover the exhaust portsto permit the egress of burned gases from the engine cylinder when thepiston is in down-stroke position, a conduit adapted to communicate airfrom the compressor to the engine cylinder through the said inlet ports,a compressor valve at the compressor end of the conduit and adapted tocontrol the communication of air under pressure between the conduit andthe compressor, said compressor and said inlet valves when closedadapted to trap air under pressure in the conduit, means for operatingthe inlet valve to effect a supply of air from the conduit to the enginecylinder after the exhaust port therefor has been uncovered by thedownward movement of the piston, said compressor valve adapted to effecta flow of air from the compressor cylinder to the conduit to superchargethe engine cylinder when the exhaust ports therefor are recovered by theengine piston during its consequent upward movement,

said inlet valve operating means adapted to reclose the inlet valve todiscontinue the supercharging of the engine after a length of timefollowin reclosure of the engine exhaust ort, and a fuel injection valvedisposed in the sad of the cylinder for periodically injecting atomizedliquid fuel, and crankshaft means for reciprocating the engine andcompressor pistons in their respective cylinders synchronously, saidcrank shaft means adaptan internal combustion engine, the

ed to efiect corresponding strokes of theme piston ahead of those of theother;

2. In an internal combustion engine, the combination with an enginecylinder, a piston reciprocable therein, a cylinder head, an inlet.

port in the cylinder head, an exhaust port through the side walls of thecylinder and adapted to be uncovered by the piston when the piston isapproaching the bottom of it's stroke, to permit the egress of burnedgases from the cylinder, a compressor comprisin a relativelytelescopable piston and cylinder or supplying air under pressure for theengine cylinder, of a conduit interconnecting the said source and theengine cylinder through the said inlet valve, of an air supply cut-ofivalve disposed at the inlet end of the said conduit and operable tocommunicate air to the conduit after the reclosure of the exhaust portof the engine cylinder by the piston when travelling on its upwardstroke, and means adapted to actuate mid inlet valve to permit flow ofcompressed air from the conduit'starting at a predetermined length oftime after uncovering of the exhaust port, and a fuel injection valvedisposed in the head of the cylinder for periodically. injectingatomized liquid fuel, the compressive stroke of the engine pistonadapted to be completed subsequently to that of the pump piston, saidpump piston stroke completed afterthe closing of said inlet valve.

3. In a two-cycle engine, the combination with a cylinder, of areciprocable piston in the cylinder, of inlet and exhaust portstherefor,

said exhaust port being disposed more remote from the head of thecylinder than the inlet port, an inlet valve for the inlet port andmeans adapted to operate the said inlet valve synchronously with themovement of the piston in the cylinder and adapted to open the inletvalve only after the exhaust port has been opened, means to supply airunder pressure to the cylinder, a conduit interconnecting the said meansand the cylinder through the said inlet port, a control valve at theinlet end of the said conduit for limiting the periods of charging ofthe conduit with the compressed air. from the source, said control valveoperatin means being operable synchronously witht episton in t may besuppllied, first, from eompresse air trapped in t e conduit by the saidinlet and control valves, and, subsequently, b air communicated to theengine throughtlie conduit ecylinder,whereb air from the source, and afuel injection valve disposed in the head of the cylinderforperiodically injecting atomized liquid fuel, said 'cglinder said drivingmeans adapted to efl'ect compression strokes of the engine pistonsubsequently to the strokes of the other piston.

riving the egress o burned gases from the cylinder when the piston is inexhaust-stroke position, a compressor comprising a reciprocating air comressing piston and a cylinder therefor, a con uit adapted to communicateair from the V compressor, in pulses, towards and into the enginecylinder through said inlet valves, a compressor valve at the compressorend of the conduit, said compressor valve and said inlet valves whenclosed adapted to trap air under. pressure in the conduit, means foroperating the inlet valve to effect a supply of air from the conduit tothe engine cylinder after the exhaust port therefor has been uncoveredby the downward movement of the piston, means to operate said compressorvalve to effect a flow of air from the compressor cylinder to theconduit to supercharge the engine cylinder when the exhaust portstherefor are recovered by the engine piston during its consequentupward. movement, said inlet valve operatin means adapted to reclose theinlet valve to 'scontinue the supercharging of the engine at the end ofa predetermined period following reclosure of the engine exhaust port, afuel injection valve disposed in the ead of the cylinder forperiodically injecting atomized liquid fuel and means to effect closureof the inlet valves during the compression stroke of the air compressingpiston and to effect closure of the compressor valve at approximatelythe end of the pump stroke.

5. The method of economically supplying air to an engine cylindercomprising the synchronous reciprocation of engine cylinder and aircompressor cylinder pistons, the compressor cylinder piston being movedon its compresion and expansion strokes ahead of the correspondingstrokes of the engine piston,

compressing air in the compressor during the compression period thereof,communicating meanwhile the compressed air to a connecting conduitleading totheengine cylinder, shutting off the conduit at its a proachand from the compressor cylinder an at its exhaust end from the enginecylinder, firing a charge including previously compressed air and-fuelin the engine cyllnder, then exhausting the roducts of combustion fromthe engine cylmder after the engine piston has moved near- 1 to the endof its exhaust stroke, then when 1 t 0 pressure in the engine cylinderapproaches minimum pressure, admitting air from the connecting conduitto the engine cylinder, while the compression c linder is shut off fromthe connecting con uit, the com ressor piston meanwhile reaching the end0 its expamion stroke and then subsequently startduit when the pressurein the interconnecting ing on its compression stroke, then effectingcommunication of the air in the compressor cylinder to that in theconnecting conduit when the increasing pressure of air in the compressorcylinder approximates that of the pressure at the time in the compressorcylinder, subsequently discontinuing the exhaust of burned gases fromthe'engine cylinder when the newly admitted air starts to flowtherefrom, then discontinuing the "admission of air to the en inecylinder, while the compression of air y the compressor continues, thendiscontinuing the communication of compressed air to the interconnectingconconduit reaches amaximum pressure, and repeating the above cycleperiodically.

6. The method of economically supplying air to an engine cylinder,comprising the compresing of air, confining the compressed aircontiguously to the cylinder while firing the charge of previouslycompressed air and fuel contained in the engine cylinder, theninitiating the exhausting of the products of combustion from the enginecylinder after the engine piston has moved nearly to the end of itsexhaust stroke, the when the pressure in the engine cylinder, resultingfrom the exhausting, approaches minimum pressure, supplying air from thesaid contiguous supply of compressed air to the engine cylinder, theninitiating the replenishment of contiguously confined compressed airwhile continuing the supply of air to the engine cylinder, subsequentlydiscontinuing the exhaustion of the products of combustion from theengine cylinder when the newly supplied air following the products ofcombustion starts to fiow therefrom, then discontinuinw the supply ofair to the engine cylinder while continuing the compressive 10.3confinement of additional air, then subsequently discontinuing thecompression, and effecting confinement of air, and repeating the abovecycle, periodically.

7. The method of periodically supplying 11o air to an engine cylinder,comprising the periodic communication of air to the cylinder from asource of air confined under pressure contiguous to the cylinder duringa certain part of the engine c cle comprising the latter 1 part of theexhaustion part of the cycle, and the subsequently occurring supercharing part of the cycle, replenishing the confined compressed air onlyduring another portion of t e engine cycle, comprising a part of thesupercharging portion of the cycle, and the 1 art of thesubsequent'engine cycle portion immediately following, discontinuingmeanwhile the supply of air to the engine cylinder .during the lastnamed subsequent portion of the engine cycle.

In testimony whereof I hereunto afiix my signature this 26th day of May,19st.

FRANK B. STEARNS.

